FWP:

For background see S. R. Faruqi's choices.
This verse is from a different, unpublished, ham-:tar;h ghazal from
1816, and is included for comparison. In the unpublished ghazal, this was the seventh and last verse.

This is a verse of what I call 'stress-shifting'. Depending on which part of the first line we choose to emphasize, the second line takes on variety of different nuances:

=he 'used to say' it, 'yesterday'-- why does he not say it today? Is it because Asad has now left this world, and is thus beyond all pain?

=the speaker is 'that confidant'-- is it something to which no outsider would be privy, if Asad had not confided in him?

=the speaker knows the 'secret/mystery'-- is Asad's anguish something far more (mystically) significant than that of any ordinary lover?

=the speaker said it 'to himself'-- because Asad is now dead? because no one else is available to hear it? willing to hear it? worthy to hear it?

=the speaker said it with an aah , a sigh-- of regret at the loss of Asad? of compassion for Asad's pain? of general melancholy at the human condition?

And then, of course, about Asad's pain of separation itself we learn absolutely nothing-- except that one shouldn't ask about it.